Metabolomic and Immunologic Discriminators of MIS-C at Emergency Room Presentation.

Multisystem Inflammatory Syndrome in Childhood (MIS-C) follows SARS-CoV-2 infection and frequently leads to intensive care unit admission. The inability to rapidly discriminate MIS-C from similar febrile illnesses delays treatment and leads to misdiagnosis. To identify diagnostic discriminators at the time of emergency department presentation, we enrolled 104 children who met MIS-C screening criteria, 14 of whom were eventually diagnosed with MIS-C. Before treatment, we collected breath samples for volatiles and peripheral blood for measurement of plasma proteins and immune cell features. Clinical and laboratory features were used as inputs for a machine learning model to determine diagnostic importance. MIS-C was associated with significant changes in breath volatile organic compound (VOC) composition as well as increased plasma levels of secretory phospholipase A2 (PLA2G2A) and lipopolysaccharide binding protein (LBP). In an integrated model of all analytes, the proportion of TCRVß21.3+ non-naive CD4 T cells expressing Ki-67 had a high sensitivity and specificity for MIS-C, with diagnostic accuracy further enhanced by low sodium and high PLA2G2A. We anticipate that accurate diagnosis will become increasingly difficult as MIS-C becomes less common. Clinical validation and application of this diagnostic model may improve outcomes in children presenting with multisystem febrile illnesses.

Developmental progression of the nasopharyngeal microbiome during childhood and association with the lower airway microbiome.

Background: The upper (URT) and lower (LRT) respiratory tract feature distinct environments and responses affecting microbial colonization but investigating the relationship between them is technically challenging. We aimed to identify relationships between taxa colonizing the URT and LRT and explore their relationship with development during childhood. Methods: We employed V4 16S rDNA sequencing to profile nasopharyngeal swabs and tracheal aspirates collected from 183 subjects between 20 weeks and 18 years of age. These samples were collected prior to elective procedures at the Children's Hospital of Philadelphia over the course of 20 weeks in 2020, from otherwise healthy subjects enrolled in a study investigating potential reservoirs of SARS-CoV-2. Findings: After extraction, sequencing, and quality control, we studied the remaining 124 nasopharyngeal swabs and 98 tracheal aspirates, including 85 subject-matched pairs of samples. V4 16S rDNA sequencing revealed that the nasopharynx is colonized by few, highly-abundant taxa, while the tracheal aspirates feature a diverse assembly of microbes. While no taxa co-occur in the URT and LRT of the same subject, clusters of microbiomes in the URT correlate with clusters of microbiomes in the LRT. The clusters identified in the URT correlate with subject age across childhood development. Interpretations: The correlation between clusters of taxa across sites may suggest a mutual influence from either a third site, such as the oropharynx, or host-extrinsic, environmental features. The identification of a pattern of upper respiratory microbiota development across the first 18 years of life suggests that the patterns observed in early childhood may extend beyond the early life window.

Timing of Nonurgent Transesophageal Echocardiography and The Risk of Embolic Events Among Patients Admitted With Infective Endocarditis. A Review of the National Inpatient Sample.

In patients hospitalized for infective endocarditis (IE), timing of nonurgent transesophageal echocardiography (TEE) to reduce embolic events (EE) is unclear. In a retrospective cohort from the 2016 to 2018 combined National Inpatient Sample (NIS), Low-risk adults with IE who underwent nonurgent (>48 hours) TEE were stratified into 3 cohorts based on the timing of the first TEE: early-TEE (3-5 days), intermediate-TEE (5-7 days) and late-TEE (>7). The primary outcome was a composite of an embolic event. Each day before TEE led to 3% increased odds of composite-embolic-events (P < 0.001), 1.21-day extra LOS (P < 0.001) and 14,186 USD increased total charge (P < 0.001). Early compared to late TEE led to reduced LOS by 10 days (P < 0.001) and total cost by 102,273 USD (P < 0.001), odds reduction of 27% in embolic strokes, 21% in septic arterial embolization and 50% reduction in preoperative time (P < 0.001). Among patients hospitalized for suspected IE, the time to TEE was correlated with increased odds of all EE, prolonged preoperative time for valve surgery, LOS, and total charge. Early TEE compared to late TEE led to the largest reduction in length of stay and total cost.

Evolution of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) seroprevalence among employees of a US academic children's hospital during coronavirus disease 2019 (COVID-19) pandemic.

OBJECTIVE: To describe the cumulative seroprevalence of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antibodies during the coronavirus disease 2019 (COVID-19) pandemic among employees of a large pediatric healthcare system. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational cohort study open to adult employees at the Children's Hospital of Philadelphia, conducted April 20-December 17, 2020. METHODS: Employees were recruited starting with high-risk exposure groups, utilizing e-mails, flyers, and announcements at virtual town hall meetings. At baseline, 1 month, 2 months, and 6 months, participants reported occupational and community exposures and gave a blood sample for SARS-CoV-2 antibody measurement by enzyme-linked immunosorbent assays (ELISAs). A post hoc Cox proportional hazards regression model was performed to identify factors associated with increased risk for seropositivity. RESULTS: In total, 1,740 employees were enrolled. At 6 months, the cumulative seroprevalence was 5.3%, which was below estimated community point seroprevalence. Seroprevalence was 5.8% among employees who provided direct care and was 3.4% among employees who did not perform direct patient care. Most participants who were seropositive at baseline remained positive at follow-up assessments. In a post hoc analysis, direct patient care (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.03-3.68), Black race (HR, 2.70; 95% CI, 1.24-5.87), and exposure to a confirmed case in a nonhealthcare setting (HR, 4.32; 95% CI, 2.71-6.88) were associated with statistically significant increased risk for seropositivity. CONCLUSIONS: Employee SARS-CoV-2 seroprevalence rates remained below the point-prevalence rates of the surrounding community. Provision of direct patient care, Black race, and exposure to a confirmed case in a nonhealthcare setting conferred increased risk. These data can inform occupational protection measures to maximize protection of employees within the workplace during future COVID-19 waves or other epidemics.

Reproducible Breath Metabolite Changes in Children with SARS-CoV-2 Infection.

SARS-CoV-2 infection is diagnosed through detection of specific viral nucleic acid or antigens from respiratory samples. These techniques are relatively expensive, slow, and susceptible to false-negative results. A rapid noninvasive method to detect infection would be highly advantageous. Compelling evidence from canine biosensors and studies of adults with COVID-19 suggests that infection reproducibly alters human volatile organic compound (VOC) profiles. To determine whether pediatric infection is associated with VOC changes, we enrolled SARS-CoV-2 infected and uninfected children admitted to a major pediatric academic medical center. Breath samples were collected from children and analyzed through state-of-the-art GCxGC-ToFMS. Isolated features included 84 targeted VOCs. Candidate biomarkers that were correlated with infection status were subsequently validated in a second, independent cohort of children. We thus find that six volatile organic compounds are significantly and reproducibly increased in the breath of SARS-CoV-2 infected children. Three aldehydes (octanal, nonanal, and heptanal) drew special attention, as aldehydes are also elevated in the breath of adults with COVID-19. Together, these biomarkers demonstrate high accuracy for distinguishing pediatric SARS-CoV-2 infection and support the ongoing development of novel breath-based diagnostics.

Discrimination of SARS-CoV-2 infected patient samples by detection dogs: A proof of concept study.

While the world awaits a widely available COVID-19 vaccine, availability of testing is limited in many regions and can be further compounded by shortages of reagents, prolonged processing time and delayed results. One approach to rapid testing is to leverage the volatile organic compound (VOC) signature of SARS-CoV-2 infection. Detection dogs, a biological sensor of VOCs, were utilized to investigate whether SARS-CoV-2 positive urine and saliva patient samples had a unique odor signature. The virus was inactivated in all training samples with either detergent or heat treatment. Using detergent-inactivated urine samples, dogs were initially trained to find samples collected from hospitalized patients confirmed with SARS-CoV-2 infection, while ignoring samples collected from controls. Dogs were then tested on their ability to spontaneously recognize heat-treated urine samples as well as heat-treated saliva from hospitalized SARS-CoV-2 positive patients. Dogs successfully discriminated between infected and uninfected urine samples, regardless of the inactivation protocol, as well as heat-treated saliva samples. Generalization to novel samples was limited, particularly after intensive training with a restricted sample set. A unique odor associated with SARS-CoV-2 infection present in human urine as well as saliva, provides impetus for the development of odor-based screening, either by electronic, chemical, or biological sensing methods. The use of dogs for screening in an operational setting will require training with a large number of novel SARS-CoV-2 positive and confirmed negative samples.

Reproducible breath metabolite changes in children with SARS-CoV-2 infection.

SARS-CoV-2 infection is diagnosed through detection of specific viral nucleic acid or antigens from respiratory samples. These techniques are relatively expensive, slow, and susceptible to false-negative results. A rapid non-invasive method to detect infection would be highly advantageous. Compelling evidence from canine biosensors and studies of adults with COVID-19 suggests that infection reproducibly alters human volatile organic compounds (VOCs) profiles. To determine whether pediatric infection is associated with VOC changes, we enrolled SARS-CoV-2-infected and -uninfected children admitted to a major pediatric academic medical center. Breath samples were collected from children and analyzed through state-of-the-art GCxGC-ToFMS. Isolated features included 84 targeted VOCs. Candidate biomarkers that were correlated with infection status were subsequently validated in a second, independent cohort of children. We thus find that six volatile organic compounds are significantly and reproducibly increased in the breath of SARS-CoV-2-infected children. Three aldehydes (octanal, nonanal, and heptanal) drew special attention, as aldehydes are also elevated in the breath of adults with COVID-19. Together, these biomarkers demonstrate high accuracy for distinguishing pediatric SARS-CoV-2 infection and support the ongoing development of novel breath-based diagnostics.

Evidence for SARS-CoV-2 Spike Protein in the Urine of COVID-19 Patients.

Background: SARS-CoV-2 infection has, as of April 2021, affected >133 million people worldwide, causing >2.5 million deaths. Because the large majority of individuals infected with SARS-CoV-2 are asymptomatic, major concerns have been raised about possible long-term consequences of the infection. Methods: Wedeveloped an antigen capture assay to detect SARS-CoV-2 spike protein in urine samples from patients with COVID-19whose diagnosis was confirmed by positive PCR results from nasopharyngeal swabs (NP-PCR+) forSARS-CoV-2. We used a collection of 233 urine samples from 132 participants from Yale New Haven Hospital and the Children's Hospital of Philadelphia that were obtained during the pandemic (106 NP-PCR+ and 26 NP-PCR-), and a collection of 20 urine samples from 20 individuals collected before the pandemic. Results: Our analysis identified 23 out of 91 (25%) NP-PCR+ adult participants with SARS-CoV-2 spike S1 protein in urine (Ur-S+). Interestingly, although all NP-PCR+ children were Ur-S-, one child who was NP-PCR- was found to be positive for spike protein in their urine. Of the 23 adults who were Ur-S+, only one individual showed detectable viral RNA in urine. Our analysis further showed that 24% and 21% of adults who were NP-PCR+ had high levels of albumin and cystatin C, respectively, in their urine. Among individuals with albuminuria (>0.3 mg/mg of creatinine), statistical correlation could be found between albumin and spike protein in urine. Conclusions: Together, our data showed that one of four individuals infected with SARS-CoV-2 develop renal abnormalities, such as albuminuria. Awareness about the long-term effect of these findings is warranted.